Magnetically operable locking device

ABSTRACT

A MAGNETICALLY OPERABLE LOCKING DEVICE HAVING LATCHING MEANS IN A HOUSING, A SPRING LOADED DETENT MEANS OF MAGNETICALLY INFLUENCED MATERIAL AND MAGNETIC MEANS FOR RELEASING THE DETENT. THE MAGNETIC MEANS EXERTS A MAGNETIC FIELD FORCE LARGE ENOUGH TO INCLUDE A MAGNETIZABLE ROLLER, THE LENGTH OF THE FORCE BEING ONLY SLIGHTLY LARGER THAN THE DISTANCE REQUIRED TO MOVE THE LATCH TO AN UNLOCKED POSITION.

March 2r H. RUDOLF ETA'- MAGNETICALLY OPERABLE LOCKING DEVICE Filed Dec.9, 1968 V//// U y United States Patent O 3,566,636 MAGNETICALLY OPERABLELOCKING DEVICE Haus Rudolf, 11 August-Lammle-Str., 7057 Leutenbach,Germany, and Gerhard Riegraf, 59 Winnender Str., 7150 Affalterbach,Germany Filed Dec. 9, 1968, Ser. No. 782,037 Int. Cl. Eb 47 00 U.S. Cl.70-276 9 Claims ABSTRACT 0F THE DISCLOSURE A magnetically operablelocking device having latching means in a housing, a spring loadeddetent means of magnetically influenced material and magnetic means forreleasing the detent. The magnetic means exerts a magnetic eld forcelarge enough to include a magnetizable roller, the length of the forcebeing only slightly larger than the distance required to move the latchto an unlocked position.

BACKGROUND AND OBJECTS This invention relates to a magnetically operablelock for doors, drawers, and strongboxes, particularly for piggy-banks,with a magnetic key which can be applied to the front of the lock.

Various magnetically operable locks of this type are known in the priorart. In these locks the tumbler or locking combinations, in the form ofmagnetically influenced balls or pins, operate only if the latter areattracted by a corresponding combination of magnetic components in anapplicable plate or magnetic key, thus making it possible to open thelock. The containers required that the balls and pins be very carefullyand accurately assembled mechanical devices which, for each individuallock, required individual parts -that must be differently designedand/or arranged.

The state of the art also shows magnetically operable locks, as dooropeners, which work without a key. Here, the bolt trap falls into thelocking plate opening due t0 the action of a tensioned spring, while thedoor is opened with the help of an electromagnet. Such locks are notsuitable for attachment to piggy-banks or the like, in particular. Theydo not offer suitable variation possibilities in this particular design.

It is the purpose of this invention to create a magnetically operablelock for doors, particularly piggy-banks of the above mentioned type,whereby the complicated closing and opening mechanism is considerably`simplified and whereby all locks are provided with the same simplelocking mechanism consisting of light-weight and inexpensively producedindividual parts, as well as activating magnets of uniform shape andsize which must always be attached at the same place on the lock, inorder to unlock the box. The latch of the magnetically operable lock ismoved out of its closing position by means of a magnetic force whichoperates against a closing or locking spring force.

GENERAL DESCRIPTION This problem is solved in the following manner: atrap or latch which consists of material that cannot be inuencedmagnetically is slidably guided in a lock housing along a base plate. Ina recess which is open toward the base plate, this latch contains amagnetically conducting sliding or rolling part, which, in case the lockis in the closed position, lies within the radius of effectiveness of amagnetic field of an electromagnet or a permanent magnet. A magnet canbe inserted in a recess which is made in the base plate and which has acertain pattern. The magnet of course has a pole or poles which aredesigned ICC in accordance with this pattern. The magnetic field of themagnet is only a little bit further away from the gliding or rollingpart than roughly about the length of the opening lift of the latch headwhich protrudes through an exit slot in the lock housing.

In this design, the magnetic key and its force lines,

which come out of one or more poles and which run perpendicularly to thedirection of movement of the latch, grasp the magnetically conductingmovable or rolling part which is lodged in the nonmagnetic latch. Theforce lines have a tendency to draw this gliding or rolling part as muchas possible into the center of the magnetic eld which is located in andin front of the middle of the pole or poles of the magnetic key. Here,the force of the pressure spring, which is coordinated with the force ofthe available electromagnet or `permanent magnet is overcome. t;

If the pressure spring which moves the latch into the closing position,is so dimeisioned that only an electro-v magnet or permanent magnet(made of an aluminumnickel-cobalt alloy) with a very high `field ofintensity, whose pole, especially provided with special recesses andraised portions accurately fits into the correspondingly designed recessin the base plate, can move the latch into its open position, then it ispractically impossible for any unauthorized person to open the box.Smaller magnets, which might likewise fit into the recess, do not haveenough force. Larger magnets will not fit into the recess and theirforce will not be suficient to influence the latch and open the lockbecause of the greater distance between them and the magneticallyconducting gliding or rolling part.

The pressure spring is best placed in a blind hole in the latch tail ina compressed state, in other words, in the locks open position.

In a further design of this invention, a shank of a locking piece,consisting of magnetically conducting flat material, can be clampedbetween the housing wall and the adjacent end of the pressure spring.The other shank of this locking piece is at an angle of about toward therst shank and runs essentially parallel to the inside of the base plateand opposite that base plate. The free end of this second shank comes torest against a stepped contact surface of the latch which points towardthe direction of the opening, when the lock is in the closed position.This contact surface of the latch has a recess at its side which pointstoward the base plate, below the blind hole containing the pressurespring, for the reception of the bent shank which can be drawn away fromthe contact surface by magnetic force.

This locking piece enables in a very simple but effective manner to makesure that the latch head cannot be pushed in by hand against the tensionof the pressure spring, `so long as the electromagnet or permanentmagnet has not been inserted or turned on.

lf, in accordance, with a further possible version of the object of thisinvention, the magnetically conducting gliding or rolling part consistsof a cylindrical roller, which is placed laterally to the direction ofthe opening lift, in the recess of the latch, -then the base plate isprovided with two outside recesses that are arranged next to each other,at an equal interval from the roller axis, in the opening position, asattachment or contact point for the two poles of a horseshoe magnet.This gives the opening force of the horseshoe magnet the desired andadequate strength.

The base plate and the lock housing are preferably made in one piece,consisting of hard, impact-resistant and breakproof plastic material. Inthe recesses of the base plate, we can provide relief-like patterns inthe form of raised circular rings, letters, or numbers. In this way, itis possible to obtain many variation possibilities for the magneticallyoperable lock. In accordance with the patterns which are providedrelief-like recesses, the associated pole surface of the electromagnetor the permanent magnet also contains correspondin-gly designed recessesand raised portions. In all of these design forms, the essential pointin the opening process is this: the force of the magnet, which isprovided with a correspondingly designed pole surface, must besuiiicient to draw the magnetically conductible rolling or gliding part,which at first is placed further away in the latch, into the densestarea of the force lines, after the angular locking piece has first beendrawn away from the contact surface along the latch so that the way canbe cleared for the latch. An additional way to make it more diflicult tounlock the box would be this: the walled thickness of the base plate inthe area of the recesses, could be made less than the integral betweenall of the other points on the base plate and the magnetically guidingroller or gliding part.

As in most cases, where banking or finance institutions hand out lockingpiggy-banks, whose keys are retained by the vsavings bank, one or moreelectromagnets or permanent magnets would be retained Iby the savingsbank also. In the case of the instant magnetic-ally operated lock, thesemagnets of course would have the specially designed pole surface.Indeed, the same electromagnet or permanent magnet could be used for allof the piggy-banks to be handed out because the owners of thepiggy-banks would hardly be in a position to open the piggy-bank withthe customary'magnetic devices.

These and other objects will be seen from the specification and drawingswherein:

FIG. l is a cross-section of a magnetically operated lock in the closedposition, shown on a scale somewhat enlarged, compared to the customarydesigns, and

FIG. 2, illustrates the device as in FIG. l, wherein the bolt-latch isin its open position by means of a magnet.

DETAILED DESCRIPTION The magnetically operable lock, shown in thesefigures, can be so inserted into the wall of a lid or a door in acontainer in a piggy-bank which can be closed and which is not shown inthe drawing, that the recesses 14 in base ,plate 1, preferably made ofplastic, will be Visible and accessible from the outside. Base plate 1thus constitutes the outer wall of lock housing 2. Protruding throughexit slot 3 of the lock wall, is a latch head 4a, which consists of anon-magnetic material, e.g., hard, breakproof plastic, and which isattached to a latch 4. Latch 4 contains a recess 5 which is open towardbase plate 1 and can be longitudinally moved in the housing. In thisrecess 5, is a gliding or rolling part 6 with low friction properties inthe form of one or more rollers or balls made of magnetically goodconducting material. It lls the height of recess 5 and rolls or glidestogether with latch 4, when the latter is moved on the smooth insidewall of base plate 1.

At the rear end of latch 4 we have a substantially cylindrical hole 12for the reception of a prestressed pressure spring 8 which is supportedalong the housing wall 9 opposite latch head 4a and which holds latch 4in the closed position.

Between housin-g wall 9 and the adjacent end of pressure spring 8, ashank 10 of a locking piece made of magnetically conducting llatmaterial is clamped. This locking piece has another shank 11 which isbent toward the first shank at an angle of about 80; this second shank11 which runs essentially parallel to the direction of movement of latch4 and is in a recess 17 of latch 4, directly above base plate 1.

When the magnetically operable lock is in the closed position, inaccordance with FIG. 1, the free end of shank 11 comes to rest against acontact surface 13 on the latch. When the lock is opened (2), it liesbetween base plate 1 and the lower surface 7 0f the rear latch position.The contact surface 13, which points toward housing wall 9, thusconstitutes a step or ledge, which is in the recess and extends all theway to the rear end of the latch and is on surface 7. Pressure spring 8,which normally holds latch 4 and its latch head 4a under prestressedcondition in a closed position, presses shank 10, and along with it theother lower shank 11 of the locking piece, in the clockwise directioninto the recess of contact surface 13 and thus enables one to make surethat the latch cannot be pushed back or drawn into its open position byhand, when the spring force is overcome.

In order to cancel out the locking effect of the locking piece, thelower shank 11 must be released from the contact surface 13 and mustcome to rest against the inside wall of base plate 1 in accordance withFIG. 2.

The recess 14 which is accessible from the outside and which is locatedin the base plate 1, serves as contact service for the pole or poles ofthe manually inserted electromagnet or permanent magnet 15.

Recess 14 conforms to the shape of the pole surface; the position ofthis recess 14 with respect to the lock housing is so selected that themagnetically conducting gliding or rolling part 6, in latch 4, when inthe closed position, already in the effective range of the magneticfield of electromagnet or permanent magnet 15, has a distance orinterval d, which is only a little bit bigger than the distance e overwhich the latch head 4a must be moved in order to open the lock. Recess14 in the base plate is so arranged, that the length of the lower shank11 of the locking piece is so selected that the latter is drawn awayfrom the contact surface 13, against the force of the pressure spring,when electromagnet or permanent magnet 15 is attached. FIG. 2 shows usthat the gliding or rolling part, when the lock is in the openingposition, is still removed from the maximum of the magnetic eld by asmaller distance d1; however, shank 11 of the locking device is alsolocated in a correspondingly effective part of the magnetic force lines,so that this illustration would roughly represent the arrangement forthe gliding or rolling part and the electromagnet or the permanentmagnet that would be best to open the magnetically operable lock.

Inside recess 14 of base plate 1 there are raised patterns 19 to whichare associated corresponding recesses in the pole surface ofelectromagnet or permanent magnet 15. These patterns can have anydesired form, i.e., cylinders, letters, or numbers so that for everylock only one pole surface, adjusted to the patterns, can be used foropening.

In place of the single-pole electromagnet or permanent magnet 15, whichis indicated in FIG. 2, there can also be used a two-pole horseshoemagnet both of whose poles are arranged in the recesses 14, one behindthe other, perpendicularly to the plane of the drawing. In this case,the magnetically conducting gliding or rolling part A6 is a roller. Themagnetic flow between the two poles is effectively closed via the rollerand represents a very strong opening force. Accordingly, the size ofrecesses 14 and of the magnets can be kept comparatively small and thetension of pressure spring 8 can be increased to exert a strong closingpressure.

To prevent the unauthorized opening of the lock, electromagnets orpermanent magnets with the greatest possible eld intensity can be used.If the size of recesses 14 and of the magnetic poles, as well as thespring force, are so dimensioned that the strongest magnets will justaccomplish the opening lift of latch 4, coupled with the simultaneousunlocking of the locking piece, then the unauthorized opening of thelock with a magnet of equal or even greater eld of intensity will bepractically impossible. This stronger magnet could be attached onlyoutside the recess 14 and its effective force lines would not operate onthe gliding or rolling part which opens` the lock.

When a so-called mortise dead lock is used then the housing wall 9 canhave a protrusion (not shown) at a place corresponding to the latch head4a of latch 4. With this protrusion, the magnetically operable lockwould come to rest under the edge of exit slot 3 and against the inside'wall of a piggy-bank. The dimensions of such a mortise dead lock willthen not be any larger than known locks of the same type which areopened with keys.

We claim:

'1. A magnetically operable locking device comprising:

(a) a housing,

(b) a latch means of non-magnetic material movable within said housing,

(c) a first magnetizable movable member in said latch means,

(d) recess means of a particular design located adjacent said latchadapted to receive magnetic means of a design complementary to saidrecess design.

(e) a latch head on said latch means protruding from said housing andmovable a predetermined distance,

(f) a pivotal locking piece of magnetizable material cooperating withsaid latch means to retain said latch means in a locked position, saidpivotal locking piece comprising a pair of connected Shanks at an angleof less than 90 to each other.

(g) said magnetic means exerting a magnetic field force large enough toinclude said magnetizable movable means, the length of said force beingonly slightly longer than said predetermined distance of said latch headwhereby said magnetizable movable means is pulled toward the center ofthe magnetic field of said magnetic means.

2. A magnetically operable locking device comprising:

(a) a housing,

(b) a latch means of non-magnetic material movable within said housing,

(c) a iirst magnetizable movable member abutting against said latchmeans for effecting movement thereof upon the application of a magneticfield to said first member,

(d) means comprising a pivotal shank of magnetizable material forabutting said latch means to lock same in a predeterminded position andbeing movable by the application of a magnetic field thereto,

(e) and rneans located adjacent said latch means and said meanscomprising a pivotal shank for positively locating a magnetic fieldapplying means, whereby the presence of said magnetic -ield applyingmeans provides a magnetic field force capable of controlling both theposition of said first magnetizable movable member and said meanscomprising a pivotal shank t effect actuation of said magneticallyoperable locking device.

3. A magnetically operable locking device as defined in claim 2 whereinsaid magnetizable movable member is a roller.

4. A magnetically operable locking device as defined in claim 2including spring biasing means operating on said latch means biasingsaid latch means into a locked position.

5. A magnetically operable locking device as defined in claim 2 whereinsaid magnetizable movable member is a roller, said latch means includesan angularly shaped recess conforming to said roller and opening towarda base plate having said design recesses therein, said roller positionedin said angularly shaped recess.

A6. A magnetically operable locking device comprising:

(a) a housing.

(b) a latch means within said housing,

(c) spring biasing means for forcing said latch means into one position,

(d) a recess in said latch means,

(e) locking means having a pair of shanks connected to each other atanangle of less than 90,

(f) said spring biasing means having one end within said latch means andanother end against one of said Shanks,

(g) the other of said shanks being engagable with said recess,

(h) said shank being of magnetizable material,

(i) magnetic means for moving said other shank out of engagement withsaid recess, and moving said latch to an unlocked position.

7. A magnetically operable locking device as defined in claim 2 whereinsaid means for positively locating a magnetic field applying meanscomprises a pair of recesses in said housing.

8. A magnetically operable locking device as deiined in claim 2 whereinsaid means comprising a pivotal shank includes a pair of connectedShanks at an angle of less than 90 to each other.

9. A magnetically operable locking device as defined in claim 2 furtherincluding a magnetic iield applying means for moving said pivotal shankto a release position and for moving said first magnetizable movablemember to enable said latch into an unlocked position.

References Cited UNITED STATES PATENTS 2,177,996 10/1939 Raymond 70-3863,056,276 10/1962 Allander 70--276 3,234,767 2/1966 Allander 70-276FOREIGN PATENTS 230,762 12/ 1963 Austria 70-276 MARVIN A. CHAMPION,Primary Examiner R. L. WOLFE, Assistant Examiner U.S. Cl. X.R. -386, 413

